I just read I Have No Mouth, and I Must Scream by Harlan Ellison in a collection of short stories called "The Mirror of Infinity". The story is about a group of people who are tortured by a computer named AM. Occasionally the text is interrupted by a long rectangle with assorted dots. Willis E. McNelly gave an analysis in the story in which he described describes this pattern "AM speaking through computer tape."
I'd describe the way they look in my copy by saying that there's a long rectangle that's big enough to contain an array of 3 rows and about 50 columns. Some positions in the array contain a black dot and others are just blank white. Some of the patterns look like Braille, except that Braille only allows 3 by 2 arrays, and there are definitely dot patterns that are at least 4 dots long without gaps in between.
Do any of you know if Ellison encoded real text in here?